Internally reinforced drawer guide

ABSTRACT

An internally reinforced, molded plastic drawer guide for chests using center-guide construction. A guide having balanced strength and stiffness is produced by distributing glass fibers substantially uniformaly throughout the body of the guide, including regions spanning the joinder of the body&#39;&#39;s component parts.

United States Patent [1 1 [11] 3,825,310 Roemer July 23, 1974 [54] INTERNALLY REINFORCED DRAWER 3,112,969 12/1963 Gustafson 312/330 GUIDE 3,363,960 1/1968 Reiss et a1 3,653,735 4/1972 Duepree 3l2/330 [75] Inventor: Bruce W. Roemer, Portland, Oreg.

[73] Assignee: Barker Manufacturing Company, Primary ExaminerCharles J Myhre Portland, Oreg. Assistant ExaminerR. H. Lazarus [22] Filed Mar 1 1973 Attorney, Agent, or Firml(olisch, Hartwell &

Dickinson [21] Appl. No.: 337,072

' [57] ABSTRACT [52] US. Cl. 308/36, 312/341 NR, 312/330 51 Int. Cl. Fl6c 21/00 Internally remforced, molded Plastic drawer gwde 58 Field of Search 308/38, 3.6; 312/342, for chests using center-guide Construction. A guide 312/343, 344, 5 346, 347, 330 341 NR having balanced strength and stiffness is produced by distributing glass fibers substantially uniformaly 5 References Cited throughout the body of the guide, including regions UNITED STATES PATENTS spanning the joinder of the bodys component parts.

3,059,986 10/1962 Miller 308/36 4 Claims, 4 Drawing Figures 1 INTERNALLY REINFORCED DRAWER GUIDE BACKGROUND AND SUMMARY OF THE INVENTION The invention relates to a drawer guide, and more particularly to a strong, lightweight molded plastic drawer guide having an internally reinforced structure.

Drawer guides of the general type contemplated by the invention are widely used in chests of drawers having so-called center guide construction. In the past, such guides have been constructed principally of wood; however, metal center guides have also been used.

Although a drawer guide is a relatively simple structure, it must satisfy a number of requirements in order to satisfactorily perform its function. For one, the guide must be strong enough to support the full weight of a drawer and its contents. In addition, the guide must have sufficient stiffness to resist deflecting excessively under load, since that could cause binding or other difficulties in opening and closing the drawer. Further, because portions of the drawer assembly slide or roll along the guide as the drawer is pushed in or pulled out, the guide should be smooth and have a low friction characteristic. Still further, since drawer guides are used in very large quantities by a highly competitive industry, they should be capable of being readily produced in large quantity at low cost. v

A general object of the present invention, therefore, is to provide a drawer guide which meets the aboveidentified needs in a practical and satisfactory manner.

BRIEF DESCRIPTION OF THE DRAWINGS Other more specific objects and advantages of the novel drawer guide of the invention will become more apparent as the description which follows is read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a fragmentary perspective view of a chest and an associated drawer, illustrating the use of the novel drawer guide;

FIG. 2 is a side view, partially in section of a drawer guide, showing mounting detail;

FIG. 3 is a bottom plan view of the drawer guide of FIG. 2; and

FIG. 4 is a transverse cross section of the guide taken on line 4-4 of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION Turning now to the drawings, illustrated in FIG. 1 are portions of a chest of drawers l incorporating center drawer guides according to the invention. Chest includes a cabinet 12 designed to accommodate a pair of drawers, with a portion of one such drawer, lower drawer 14, shown removed from the cabinet. Cabinet 12 includes upper and lower drawer-receiving chambers 16, 18, respectively. Since, in the cabinet illustrated, chambers 16 and 18 are identical in all essential respects, the description following will, for brevity, be addressed to chamber 18 alone, but apply equally to both.

Mounted adjacent the bottom of chamber 18 on front and rear cabinet cross-members 22, 24 respectively, is an elongate drawer guide 20. As will be appreciated, guide is disposed substantially normal to the cross-members about midway between the ends of the chamber. Referring to FIGS. 2-4, drawer guide 20 has a unitary body comprising an elongate intermediate portion 20a and a pair of mounting or end portions 20b, 20c integrally joined to either end of the intermediate portion. An elongate, generally horizontally disposed central web 26 extends substantially the length of the guide body. Integral with the web and extending the length of either side thereof are a pair of upstanding side rails 28, 30. Also extending the length of web 26 are a pair of laterally spaced, depending flanges 32, 34 (FIG. 4), integrally joined to the web laterally inward of side rails 28, 30 respectively. Web 26, side rails 28, 30 and flanges 32, 34 mutually terminate at end walls 36, 38 of end portions 20b, 200 respectively.

Referring now to FIGS. 2 and 3, flanges 32,34 each include intermediate portions 32a, 34a respectively, extending the length of intermediate guide portion 20a. Portions 32a, 34a are joined at either end by connecting walls 40, 42 adjoining each end portion of the guide. Flanges 32, 34 also include end portions extending substantially the length of the guides end portions. Thus, end portions 32b, 34b of the flanges extend along guide portion 20b between connecting wall 40 and end wall 36. In like manner, flange end portions 32c, 34c extend along guide portion 20c between connecting wall 42 and end wall 38. Connecting flange portions 32b, 34b intermediate walls 36, 40 is a connector block 44. Block 44 has a bore 45 therein to accommodate an attaching device or fastener such as a-screw 46 (FIG. 2). Similarly, end portions 320, 34c are connected through connector block 48 having a bore 49 therein.

Referring again to FIGS. 2-4, drawer guide 20 further includes a pair of elongate ribs or beads 50, 52 depending from side rails 28, 30, respectively. Beads 50, 52 extend along the guide body on either side, terminating, as shown in FIGS. 2 and 3, at locations generally intermediate the connecting walls and connector blocks.

As best shown in FIG. 2, the end portions of the guide body are distinctly shallower than the intermediate portion. Thus, the lower margins of an end portion form, with the adjoining connecting wall, what may be thought of as an inverted shelf or seat for a' cabinet cross-member. These seats adapt the end portions of the guide for supporting the intermediate portion between transversely extending, generally coplanar cabinet members, such as cross-members 22, 24. It may be noted that the seats formed in the opposite ends of a guide need not be identical. Thus, in FIG. 2, the seat for cross-member 24 is somewhat shallower than that for cross-member 22 to accommodate the greater thickness.of member 22.

With guide 20 mounted in cabinet 12 as shown in FIG. 1, drawer 14 may be inserted into chamber 18. Suitably attached to the bottom surface of drawer 14 is an elongate inverted channel member or rider 54 having the cross-sectional configuration shown in phantom outline in FIG. 4. As drawer 14 is inserted into chamber 18, rider 54 loosely captures the upper portion of guide 20. As the drawer is pushed into the chamber, rider 54 rides along the guide, preventing misalignment between the drawer and cabinet.

As will be appreciated, as a drawer is inserted into or 3 FIG. 4 view, but will slide along the guides side rail and bead portions. It is desirable, therefore, that these portions have a smooth, low friction surface. This is provided in the drawer guide of the invention by molding the guide from a suitable plastic composition such as a polystyrene composition.

As pointed out above, a drawer guide for a cabinet employing center-guide contruction must be both stiff and strong, since a large portion of the weight of a drawer and its contents is carried by the guide. Obviously, the guide must be strong enough to support the weight of a fully loaded drawer in any position between fully inserted and fully withdrawn. In addition, the

guide must be stiff enough not to sag or bend excessively as the drawer is inserted or withdrawn. Too much deflection, either vertical or lateral prevents smooth insertion and withdrawal, and could cause jamming of thedrawer in the cabinet chamber. To provide these qualities, glass fibers are dispersed throughout the plastic material comprising the drawer guide body. Preferably, the glass fibers are substantially uniformly dispersed throughout the body, including regions in the intermediate portion of the guide spanning the joinder of the side rails and flanges with the web. In the end portions of the guide, fibers are dispersed throughout the regions encircling the mounting bores, and spanning the joinder of the end portions with the intermediate portion. In this way, a strong, unified, internally reinforced structure is produced.

A preferredmethod for accomplishing the desired distribution of glass fibers throughout the body of the guide is provided by forming the part by injection molding. Thus, drawer guides meeting the requirements generally set out above are produced by forming the guides frorna polystyrene composition containing a minor proportion of glass fibers using conventional injection molding equipment. As will be appreciated, the-conditions under which the guides are molded depend on the particular equipment'used, guide size and shape, mold design, and other factors well known to those having ordinary skill in that art, and thus play no partof the invention.

The specific polystyrene composition used and the proportion of glass fibers incorporated therein depend on the particular geometry of the drawer guide and its intended use conditions. In general, however, it has not been found desirable to add more than about percent by weight of glass fibers to a general purpose polystyrene composition, and with high-impact polystyrene compositions a range of about 3 to about 7 percent by weight is preferred. Greater amounts of fibers produce guides having greater stiffness but decreased strength. Guides produced with lower amounts are overly flexible.

Describing a particular manufacture by way of example, however, drawer guides having the configuration shown in the drawings are produced from a highimpact grade polystyrene composition, such as Amoco Grade H4R polystyrene resin, to which about 3 to about 7 percent by weight of glass fibers hasbeen added. The preferred method of incorporating the glass fibers in the composition is to admix a polystyrene resin containing a high percentage of fibers, such as Fiberfil Styracon, a resin containing about 80 percent by weight long (one-half inch) glass fibers, with the highimpact resin. Thus, to obtain a high-impact composition containing about 5 percent by weight of glass fibers, 15 pounds of Grade H4R resin pellets are admixed with l pound of Styracon pellets. This mixture, containing in addition a suitable coloring agent, is added to the hopper of a screw-type injection molding machine.

As is generally understood, the hoppers outlet communicates with the rear end of a hollow, heated cylinder or barrel containing an elongate, rotating screw. As the polystyrene pellets flow into the barrel, they are captured by the screw and carried forward. in the heated barrel the two types of peliets melt and are mixed together to form a uniform composition. When the polystyrene composition has been heated to the desired molding temperature, about 325 to 340 F. for the particular mixture described herein, it is injected through an orifice into a mold or die for the drawer guideThe composition is preferably injected adjacent one end of the die. As the glass-containing composition flows through the guide-shaped cavity in the die, the glass fibers in the composition tend to align themselves in the direction of flow. Thus, the fibers in the intermediate portion of the guide become oriented generally in the direction of that portions longitudinal axis as the composition flows from one end of the cavity to the other. In like manner, a portion of the fibers in the end portions become oriented around the bore-defining regions of those portions.

There is thus provided a drawer guide meeting the aboveidentified requirements in a practical and satisfactory manner. Although a preferred embodiment has been described herein, it isunderstood that variations and modifications are possible without departing from the spirit of the invention.

It is claimed and desired to be secured by Letters Patent l. A drawer guide including an elongate intermediate portion comprising an inverted U-shaped channel member having a pair of laterally outwardly projecting integral side rails disposed along the members upper margin, said portion comprising a polystyrene composition containing a minor proportion of glass fibers dispersed throughout said channel member and side rails, and oriented generally in the direction of said portions longitudinal axis and, mounting portions integrally joined to the intermediate portion adjacent either end thereof and adapted for supporting the intermediate portion between transversely extending, generally coplanar cabinet members, said mounting portions each including means defining a bore therein to accommodate means for attaching the guide to a cabinet member, each of said mounting portions comprising a polystyrene composition containing a minor proportion of glass fibers dispersed therein, said fibers being distributed in regions encircling said bores and spanning the joinder of said monting portions with said intermediate portion, whereby said bore-defining means is reinforced and a strong, unified, internally reinforced structure is produced.

2. The drawer guide of claim 1, wherein said polystyrene composition comprises a high impact polystyrene composition containing about 3 to about 7 percent by weight of glass fiber.

3. A unitary, internally reinforced drawer guide comprising an elongate intermediate portion including a pair of laterally spaced upstanding side rails integrally joined along their opposing lower margins by a horizontally disposed central web, and a pair of substantially vertically depending, laterally spaced flanges integrally joined to said web laterally inward of said side rails, said intermediate portion comprising a polystyrene composition having about 3 to about percent by weight of glass fibers substantially uniformly dispersed therein including regions spanning the joinder of said rails and flanges with said web thus to reinforce said intermediate portion, and

a pair of mounting portions integrally joined to said intermediate portion adjacent either end thereof,

rene composition comprises a high impact polystyrene composition containing about 3 to about 7 percent by weight of glass fiber. 

1. A drawer guide including an elongate intermediate portion comprising an inverted U-shaped channel member having a pair of laterally outwardly projecting integral side rails disposed along the member''s upper margin, said portion comprising a polystyrene composition containing a minor proportion of glass fibers dispersed throughout said channel member and side rails, and oriented generally in the direction of said portion''s longitudinal axis and, mounting portions integrally joined to the intermediate portion adjacent either end thereof and adapted for supporting the intermediate portion between transversely extending, generally coplanar cabinet members, said mounting portions each including means defining a bore therein to accommodate means for attaching the guide to a cabinet member, each of said mounting portions comprising a polystyrene composition containing a minor proportion of glass fibers dispersed therein, said fibers being distributed in regions encircling said bores and spanning the joinder of said monting portions with said intermediate portion, whereby said bore-defining means is reinforced and a strong, unified, internally reinforced structure is produced.
 2. The drawer guide of claim 1, wherein said polystyrene composition comprises a high impact polystyrene composition containing about 3 to about 7 percent by weight of glass fiber.
 3. A unitary, internally reinforced drawer guide comprising an elongate intermediate portion including a pair of laterally spaced upstanding side rails integrally joined along their opposing lower margins by a horizontally disposed central web, and a pair of substantially vertically depending, laterally spaced flanges integrally joined to said web laterally inward of said side rails, said intermediate portion comprising a polystyrene composition having about 3 to about 10 percent by weight of glass fibers substantially uniformly dispersed therein including regions spanning the joinder of said rails and flanges with said web thus to reinforce said intermediate portion, and a pair of mounting portions integrally joined to said intermediate portion adjacent either end thereof, each portion including means defining a bore therein to accommodate attaching means, said mounting portions comprising a polystyrene composition having about 3 to about 10 percent by weight of glass fibers substantially uniformly dispersed therein including regions encircling said bores and spanning the joinder of said mounting portions with said intermediate portion, whereby a strong, unitary, internally reinforced drawer guide is produced.
 4. The drawer guide of claim 3, wherein said polystyrene composition comprises a high impact polystyrene composition containing about 3 to about 7 percent by weight of glass fiber. 